The present invention relates to bipolar electric coagulating and dissecting tweezers used for hemostasis and dissection in the case of a surgical operation, mainly in the case of a cranial-nerve surgical operation.
In the case of a surgical operation, particularly a blood vessel operation in a neurosurgery, a pair of bipolar electric coagulating and dissecting tweezers has been used so far which comprise two arms provided with bipolar electrodes insulated each other and connected to a high-frequency generator and energized so that bipolar electric coagulating and dissecting portions at the front ends of the arms are normally kept open and in which an insulating film is formed except the bipolar electric coagulating and dissecting portions at the front ends of the arms. Therefore, it is possible to coagulate or dissect a living tissue by holding the living tissue by the bipolar electric coagulating and dissecting portions at the front ends of the arms of the tweezers and supplying a high-frequency current.
A perfusion tube is set to the inside of either of the arms of the tweezers and a physiological saline solution or other liquid is discharged to lower the temperature produced at the time of coagulation and dissection due to the supplied high frequency. Therefore, the perfusion tube minimizes the damage of the living tissue. Moreover, the perfusion tube prevents coagulation and dissection performances from deteriorating due to the fact that the cauterized living tissue attaches to the bipolar electric coagulating and dissecting portions at the front ends of the arms of the tweezers.
However, in the case of actual surgical operations, particularly in the case of the surgical operations of a meningioma and a cerebral deformation (AVM) in the cranial-nerve surgical operation, the coagulating operation is frequently continued for a relatively long time and moreover, the opening of the perfusion tube at its front end is set nearby the bipolar electric coagulating and dissecting portions at the front ends of the arms of the tweezers. Therefore, the opening of the perfusion tube at its front end is clogged with the tissue cauterized by the tweezers during the coagulating and dissecting operation and perfusate is easily discharged and moreover, the perfusate becomes drips midway and the drips intermittently fall. Thereby, the perfusate is not constantly supplied to the bipolar electric coagulating and dissecting portions at the front end of the arms of the tweezers and thus, a state occurs in which the cauterized tissue easily attaches to the portions. Therefore, if the state occurs, a surgical operation is interrupted and an assistant wipes the cauterized tissue. However, because the opening of the perfusion tube at its front end is formed like a hole, the cauterized tissue enters the hole and thus, it cannot easily be removed. Therefore, the discharge rate of the perfusate is slowly decreased in approx. 30 min and thus, a plurality of pairs of tweezers must previously be prepared to perform the surgical operation while frequently replacing tweezers.
Moreover, in the case of a surgical operation for approaching a deep portion of a brain, it may be necessary to secure a visual field through a small gap between the both arms of a pair of tweezers. However, because the opening of a perfusion tube at its front end is formed like a hole and the bipolar electric coagulating and dissecting portions at the front ends of the arms of the tweezers are flat, drips are formed due to the surface tension of the perfusate and interrupt the visual field of the small gap. Moreover, because the drips are produced nearby the bipolar electric coagulating and dissecting portions at the front ends of the arms of the tweezers holding the living tissue to perform the coagulating operation, the bipolar electric coagulating and dissecting portions at the front ends of the both arms of the tweezers contact the perfusate drips. Because the perfusate mainly uses a physiological saline solution having a conductivity, a high-frequency current is short-circuited due to the physiological saline solution serving as a medium and thus, a high-frequency current for preventing a living tissue from being coagulated or dissected is supplied to the bipolar electric coagulating and dissecting portions at the front ends of the arms of the tweezers.
Moreover, the perfusion tube is frequently clogged due to crystallization of common salt under a standby state because the inside diameter of the opening of the perfusion tube at its front end is as small as 0.60 mm and thereby, a state frequently occurs in which no perfusate is discharged during a surgical operation.
Therefore, because the above various troubles occur, problems occur that a surgical operation time must be increased and a large load is applied to not only a patient but also a surgical operator.
It is an object of the present invention to provide a pair of bipolar electric coagulating and dissecting tweezers capable of preventing a perfusion tube from being clogged and securing a sufficient visual field of a surgical operator and moreover capable of stably and effectively supplying a high-frequency current mainly in a cranial-nerve surgical operation using a microscope.